The present invention relates to an organic shell blank that can be used, for example, to manufacture a decorative inlay, and a method for making such an organic shell blank. More particularly, the invention relates to organic shell inlay blanks made from a plurality of pieces of organic shell matter, and a method for joining those pieces together.
Inlays and overlays made from organic shells, such as abalone, oyster, etc., have been used for many years as decorative items on objects such as musical instruments, furniture, and cutlery. As used herein, an "overlay" is a shell portion thin enough that, when placed atop a smooth surface, the smooth surface can be coated with a finish material such as lacquer until the top surface of the overlay is flush with the lacquer coating the smooth surface. Typically, overlays are no thicker than about 0.015 inches, and are usually about 0.004-0.006 inches. As used herein, an "inlay" is a shell portion thick enough that building up a smooth surface adjacent the shell portion with lacquer would be difficult or impossible. Thus, an inlay would undesirably protrude from the smooth surface if not inlaid into a depression in the surface. Typically, inlays are thicker than about 0.015 inches, and may be as thick as 0.25 inches or more, limited ultimately by the size and curvature of the shell from which the inlay is taken.
As shown in FIG. 8, inlays and overlays are usually made from substantially flat or slightly rounded portions A of a shell B that are ground until flat. If an inlay is desired, each shell portion A is ground until it has the desired thickness. If an overlay is desired, the shell portion A may be ground to the desired overlay thickness, or ground to a larger thickness (such as that shown) and then sliced to a desired overlay thickness. In making such inlays or overlays, the area of any substantially flat or slightly rounded shell portion A that can be cut from the shell B is necessarily limited by the shell's thickness and curvature. Also, much of the shell B may be wasted because of the large area C that must be ground or trimmed off the shell to derive various small pieces from a large shell, so that any single piece is not overly curved.
As shown in FIG. 9, in order to obtain larger overlays, a curved portion D larger than the substantially flat or slightly rounded portion A described above can be cut from a shell E. The curved shell portion D can be sliced, parallel to the curvature, into curved veneers F having a thickness suitable for use as an overlay. The curved veneers F, being thin or flexible, are flattened, and can be glued together to form an overlay sheet.
The use of such overlay sheets is known in the Orient as raden or kaisuri (Japanese); lo-tian (Chinese); and najon (Korean). The overlay shell is classified according to its thickness, thinnest to thickest, as follows: aogai, kinuzuri, uso-gai, atsu-gai, and maru-gai.
However, the overlay sheets described above have several drawbacks. First, the thin sheets (0.004 to 0.015 inches thick) can be difficult to sand and trim because they are very brittle.
This brittleness also makes working with larger sheets difficult, making unintentional breakage a problem.
Second, using some types of shell, these thin sheets become too transparent, and the seams between joined pieces become too obvious.
Third, the sheets are not suitable for use as inlays, which are often inlaid into a mounting surface with some part of the inlay extending from the surface, and then shaped to be flush with the surface by, for example, sanding the extending part until it is flush with the surface. Overlay sheets are too thin to be sanded without being broken or completely sanded off. This problem is especially heightened when placing shell into a curved surface.
Traditional inlays are also subject to several drawbacks. First, the size of the individual inlay pieces is limited by shell curvature.
Second, because shell coloration often varies layer by layer through the shell, grinding a shell into a flat piece may entail passing through many differently colored layers around the perimeter of the piece, leading to an uneven appearance.